CORNISH: YouTube, the website that made its name as the place where you can broadcast yourself, is on the verge of launching a subscription service. NPR's Laura Sydell joins us now to talk more about it. And, Laura, what is YouTube up to?

LAURA SYDELL, BYLINE: My sources are telling me that initially, this is going to be kind of a limited. But essentially, what they're going to do is put up a paywall, meaning, if you want to see certain content, you're going to have to put in your credit card and pay a fee. And according to several reports, viewers could subscribe to a channel for as little as $1.99 a month.

CORNISH: But why are they doing it?

SYDELL: I think it's been a planned evolution. Back in 2011, YouTube added a pay-for-movies feature. A couple years ago, they laid out more than $100 million and gave it to professionals to create content for YouTube. So Madonna oversaw the development of a dance channel, and the money from those channels has been coming from advertising.

But the revenue remains well below what traditional TV makes from advertising, so I think this is an opportunity, perhaps, to try a different kind of pay model.

CORNISH: But we're all used to getting content for free on YouTube. What sort of content do they think someone's going to pay for?

SYDELL: Hah, good question. You know, I spoke with one analyst, and that's exactly what he was wondering. But he also mentioned some intriguing possibilities. For example, you could have a San Francisco Giants channel that had backstories about the players, conversations about what was going on in the locker room -before and after - and it's the kind of content that, you know, a die hard fan might really pay for but wouldn't really work on traditional TV because it's kind of too narrowly focused.

CORNISH: And it seems like the world of online content that you can pay for is growing - I mean, Netflix, Hulu, Amazon and now YouTube.

SYDELL: Exactly. And the number of subscribers to Hulu doubled to four million. And Netflix has been growing, so I think it's a question now of how many places do you want to subscribe as we move forward. But there's going to be a lot more of this.